A Sports体育运动
Many animals engage in play，but homo sapiens is the only animal (1) have invented sports.Since sports are an invention，a part of culture (2) than an aspect of nature，all definitions of sports are somewhat arbitrary. (3) sports are a human universal found in every known culture or a (4) unique to modern society depends upon one’s definition of sports.Men and (5) have always run，jumped，climbed，lifted，thrown， and wrestled，but they have (6) always performed these physical activities competitively. Although all literate societies seem to (7) contests of one sort or another in which men， and sometimes women， (8) in displays and tests of physical skill and prowess，sports may be (9) defined as physical contests performed for their own sake and not for (10) ulterior end.According to this strict definition，neither Neolithic hunters nor contestants (11) religious ceremonies such as the ancient Olympic Games were engaged in sports. (12) on the stipulation that sports must be performed for their own sake (13) the paradoxical elimination of many activities which are usually thought of as (14) ，such as exercises done for the sake of cardiovascular fitness，races run (15) satisfy a physical education requirement，ball games played to earn a paycheck. (16) definition also means abandonment of the traditional usage in which"sport，"derived (17) Middle English disporter，refers to any light hearted recreational activity.In the. (18) of some 18th- century aristocrats，a game of backgammon and the seduction of (19) milkmaid were both considered good sport，but this usage of the term (20) become archaic.

测量电源电动势和内电阻的器材如图A所示，请用实线表示导线，将图中器材连成实验用电路，实验时经测量得出的数据如下表，请在下图B的方格纸上画出U-I图线，利用图线求出电源电动势E=______ V，内电阻r=______Ω